1. Field of the Invention
This invention relates to an improvement in hydrocarbon conversion processes wherein a catalyst is contacted with a hydrocarbon feedstock in a reactor under fluidizing conditions and then removed and sent to a regenerator for removal of carbonaceous material therefrom while under fluidizing conditions.
2. Discription of the Prior Art
U.S. Pat. No. 2,913,402 discloses a fluid catalytic cracking process which comprises hydroforming hydrocarbon fractions by contacting the hydrocarbon fractions with a catalyst comprising molybdenum oxide supported on alumina. The main idea in the patent is to eliminate the loss of molybdenum oxide catalyst in the regenerator and the idea comprises cooling the regenerator in the dilute phase of the upper part of a regeneration zone to a temperature below 1000.degree. F.
U.S. Pat. No. 3,808,121 describes a regeneration process for a hydrocarbon conversion catalyst used in a fluidized catalytic cracking unit. In the regeneration process, solid form cracking catalyst is subjected to exothermic reaction conditions in the presence of solids of larger particle size, e.g. Berl saddles and Raschig rings. The large size particles comprise a carbon monoxide oxidation catalyst and act as a heat sink. In operation, the finely divided cracking catalyst is passed through the voids in the oxidation catalyst wherein the carbonaceous material is removed.
U.S. Pat. No. 3,235,512 discloses that platinum supported on silica, alumina and gamma alumina catalysts can be used in reforming gasolines and naphtha fractions, but that the mechanical strength of the catalyst is undesirable.
Belgian Pat. No. 820,181 relates to an improved (promoted) cracking catalyst for a fluidized bed cracking process. The gist of the disclosure is that a Group V, Group VI, or Group VIII metal, preferably platinum, when incorporated into a cracking catalyst in a proportion of from about 0.1 to 50 ppm enhances the oxidation of carbonaceous material from the cracking catalyst during regeneration while not substantially affecting the performance thereof.
U.S. Pat. No. 3,856,659 discloses a multiple reactor fluid catalytic cracking system which uses a dual cracking catalyst composition. The dual cracking catalyst comprises a cracking catalyst having a relatively large pore size and one having a relatively small pore size,, generally of a crystalline alumino-silicate composition.